Update about.html version history, fix API exports

About page:
- Version history now shows v4.1.2 prominently with accordion for older versions
- Shortened 'Error Correction Reed-Solomon' to 'DCT ECC / RS Code'
- Removed v4.1 badges from established features

API fixes:
- Export MAX_FILE_PAYLOAD_SIZE from constants
- Export calculate_capacity_by_mode from steganography

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontends/web/templates/about.html

@@ -100,7 +100,7 @@
                                     <li><strong>Output:</strong> JPEG or PNG</li>
                                     <li><strong>Color:</strong> Color or grayscale</li>
                                     <li><strong>Speed:</strong> ~2s</li>
-                                    <li><strong>Error Correction:</strong> Reed-Solomon <span class="badge bg-info ms-1">v4.1</span></li>
+                                    <li><strong>Error Correction:</strong> Reed-Solomon</li>
                                 </ul>
                                 <hr>
                                 <div class="small">
@@ -375,29 +375,42 @@
                 <h5 class="mb-0"><i class="bi bi-clock-history me-2"></i>Version History</h5>
             </div>
             <div class="card-body">
-                <div class="table-responsive">
+                <!-- Current Version - Prominent -->
-                    <table class="table table-dark table-sm small">
+                <div class="alert alert-success mb-4">
-                        <thead>
+                    <div class="d-flex align-items-center">
-                            <tr>
+                        <span class="badge bg-success fs-6 me-3">v4.1.2</span>
-                                <th>Version</th>
+                        <div>
-                                <th>Changes</th>
+                            <strong>Progress bars</strong> for encode operations,
-                            </tr>
+                            <strong>mobile-responsive polish</strong>,
-                        </thead>
+                            DCT decode bug fix, release validation script
+                        </div>
+                    </div>
+                </div>
+
+                <!-- Previous Versions - Accordion -->
+                <div class="accordion" id="versionAccordion">
+                    <div class="accordion-item bg-dark">
+                        <h2 class="accordion-header">
+                            <button class="accordion-button collapsed bg-dark text-light py-2" type="button"
+                                    data-bs-toggle="collapse" data-bs-target="#olderVersions">
+                                <i class="bi bi-archive me-2"></i>Previous Versions
+                            </button>
+                        </h2>
+                        <div id="olderVersions" class="accordion-collapse collapse" data-bs-parent="#versionAccordion">
+                            <div class="accordion-body p-0">
+                                <table class="table table-dark table-sm small mb-0">
                                     <tbody>
+                                        <tr>
+                                            <td width="80"><strong>4.1.1</strong></td>
+                                            <td>DCT RS format stability, Docker cleanup, first-boot wizard</td>
+                                        </tr>
                                         <tr>
                                             <td><strong>4.1.0</strong></td>
-                                <td>
+                                            <td>Reed-Solomon error correction for DCT, majority voting headers</td>
-                                    <strong>Reed-Solomon error correction</strong> for DCT mode (corrects up to 16 byte errors per 223-byte chunk),
-                                    majority voting on length headers, improved robustness with problematic carrier images
-                                </td>
                                         </tr>
                                         <tr>
                                             <td><strong>4.0.0</strong></td>
-                                <td>
+                                            <td>Channel keys, DCT default, subprocess isolation</td>
-                                    <strong>Channel keys</strong> for group/deployment isolation,
-                                    DCT default, simplified auth, passphrase replaces day_phrase,
-                                    4-word default, JPEG fix, large image support, subprocess isolation, Python 3.10-3.12
-                                </td>
                                         </tr>
                                         <tr>
                                             <td>3.2.0</td>
@@ -408,16 +421,8 @@
                                             <td>DCT mode, JPEG output, color preservation</td>
                                         </tr>
                                         <tr>
-                                <td>2.2.0</td>
+                                            <td>2.x</td>
-                                <td>QR code RSA key import/export</td>
+                                            <td>Web UI, REST API, RSA keys, QR codes, file embedding</td>
-                            </tr>
-                            <tr>
-                                <td>2.1.0</td>
-                                <td>File embedding, compression</td>
-                            </tr>
-                            <tr>
-                                <td>2.0.0</td>
-                                <td>Web UI, REST API, RSA keys</td>
                                         </tr>
                                         <tr>
                                             <td>1.0.0</td>
@@ -428,6 +433,9 @@
                             </div>
                         </div>
                     </div>
+                </div>
+            </div>
+        </div>
         
         <div class="card mb-4">
             <div class="card-header">
@@ -553,9 +561,8 @@
                     <div class="col-6 col-md-4 col-lg-2 mb-3">
                         <div class="p-3 bg-dark rounded h-100">
                             <i class="bi bi-bandaid text-info fs-3 d-block mb-2"></i>
-                            <div class="small text-muted">Error Correction</div>
+                            <div class="small text-muted">DCT ECC</div>
-                            <strong>Reed-Solomon</strong>
+                            <strong>RS Code</strong>
-                            <span class="badge bg-info ms-1">v4.1</span>
                         </div>
                     </div>
                 </div>

src/stegasoo/__init__.py

@@ -45,6 +45,7 @@ from .image_utils import (
 
 # Steganography functions
 from .steganography import (
+    calculate_capacity_by_mode,
     compare_modes,
     has_dct_support,
     will_fit_by_mode,
@@ -92,6 +93,7 @@ from .constants import (
     EMBED_MODE_LSB,
     FORMAT_VERSION,
     LOSSLESS_FORMATS,
+    MAX_FILE_PAYLOAD_SIZE,
     MAX_IMAGE_PIXELS,
     MAX_MESSAGE_SIZE,
     MAX_PASSPHRASE_WORDS,
@@ -149,6 +151,7 @@ from .validation import (
 MIN_MESSAGE_LENGTH = 1
 MAX_MESSAGE_LENGTH = MAX_MESSAGE_SIZE
 MAX_PAYLOAD_SIZE = MAX_MESSAGE_SIZE
+# MAX_FILE_PAYLOAD_SIZE imported from constants above
 SUPPORTED_IMAGE_FORMATS = LOSSLESS_FORMATS
 LSB_BYTES_PER_PIXEL = 3 / 8
 DCT_BYTES_PER_PIXEL = 0.125
@@ -188,6 +191,7 @@ __all__ = [
     "has_argon2",
     # Steganography
     "has_dct_support",
+    "calculate_capacity_by_mode",
     "compare_modes",
     "will_fit_by_mode",
     # QR utilities
@@ -252,6 +256,7 @@ __all__ = [
     "MAX_MESSAGE_LENGTH",
     "MAX_MESSAGE_SIZE",
     "MAX_PAYLOAD_SIZE",
+    "MAX_FILE_PAYLOAD_SIZE",
     "MIN_IMAGE_PIXELS",
     "MAX_IMAGE_PIXELS",
     "SUPPORTED_IMAGE_FORMATS",